From 6fe3ceb0ee204f2820899ef4b4f694d38164f7d3 Mon Sep 17 00:00:00 2001
From: Aman Agrawal <amanagr@zulip.com>
Date: Sat, 9 Nov 2024 23:23:52 +0530
Subject: [PATCH] recent_view: Fix backfill data not updated after reload.

This fixes backfill data not being inserted in recent view if
recent view was open when it received the backfill data.

Fixed by inserted rows in the sorted order instead of inserting
them randomly which caused rows to not be inserted if there were
no rows around the row being inserted.
---
 web/src/list_widget.ts    | 19 +++++++++++++++++--
 web/src/recent_view_ui.ts | 12 +++++++++---
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/web/src/list_widget.ts b/web/src/list_widget.ts
index 62d197d1e9..34d98aa9f3 100644
--- a/web/src/list_widget.ts
+++ b/web/src/list_widget.ts
@@ -541,8 +541,23 @@ export function create<Key, Item = Key>(
                     const $target_row = opts.html_selector!(meta.filtered_list[insert_index - 1]!);
                     $target_row.after($(rendered_row));
                 } else {
-                    const $target_row = opts.html_selector!(meta.filtered_list[insert_index + 1]!);
-                    $target_row.before($(rendered_row));
+                    let $target_row = opts.html_selector!(meta.filtered_list[insert_index + 1]!);
+                    if ($target_row.length !== 0) {
+                        $target_row.before($(rendered_row));
+                    } else if (insert_index > 0) {
+                        // We don't have a row rendered after row we are trying to insert at.
+                        // So, try looking for the row before current row.
+                        $target_row = opts.html_selector!(meta.filtered_list[insert_index - 1]!);
+                        if ($target_row.length !== 0) {
+                            $target_row.after($(rendered_row));
+                        }
+                    }
+
+                    // If we failed at inserting the row due rows around the row
+                    // not being rendered yet, just do a clean redraw.
+                    if ($target_row.length === 0) {
+                        widget.clean_redraw();
+                    }
                 }
                 widget.increase_rendered_offset();
             }
diff --git a/web/src/recent_view_ui.ts b/web/src/recent_view_ui.ts
index 0fa6f5608a..42a83535f1 100644
--- a/web/src/recent_view_ui.ts
+++ b/web/src/recent_view_ui.ts
@@ -923,10 +923,16 @@ export function bulk_inplace_rerender(row_keys: string[]): void {
     // we ensure the list remains sorted after insertion.
     topics_widget.replace_list_data(get_list_data_for_widget(), false);
     topics_widget.filter_and_sort();
-    for (const key of row_keys) {
-        inplace_rerender(key, true);
+    // Iterate in the order of which the rows should be present so that
+    // we are not inserting rows without any rows being present around them.
+    for (const topic_data of topics_widget.get_current_list()) {
+        const msg = message_store.get(topic_data.last_msg_id);
+        assert(msg !== undefined);
+        const topic_key = recent_view_util.get_key_from_message(msg);
+        if (row_keys.includes(topic_key)) {
+            inplace_rerender(topic_key, true);
+        }
     }
-
     setTimeout(revive_current_focus, 0);
 }